<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>UpdateElementRendering</title>
    <script src="https://cdn.bootcss.com/react/16.4.0/umd/react.development.js"></script>
    <script src="https://cdn.bootcss.com/react-dom/16.4.0/umd/react-dom.development.js"></script>
    <script src="https://cdn.bootcss.com/babel-standalone/6.26.0/babel.min.js"></script>
</head>
<body>
<div id="example"></div>
<script type="text/babel">
    function tick() {
        const element = (
            <div>
                <h1>
                    HelloWorld!
                </h1>
                <h2>
                    Now&nbsp;Time&nbsp;Is&nbsp;{new Date().toLocaleTimeString()}.
                </h2>
            </div>
        );
        ReactDOM.render(
            element,
            document.getElementById('example')
        );
    }
    setInterval(tick, 5);
</script>
</body>
</html>